Theaflavin (catechin dimer joined at B rings) and its derivatives, known collectively as theaflavins, are antioxidant polyphenols Flavan-3-ols formed from catechins during enzymatic oxidation (fermentation). Theaflavins generally comprise a mixture of theaflavin, theaflavin-3-gallate, theaflavin-3′-gallate and theaflavin-3,3′-digallate.
Theaflavins have positive health benefits directly linked to the antioxidant properties of these compounds. The benefits include the ability to effect lower blood lipid levels (e.g. cholesterol), control of inflammation, as well as anti-tumor effects. See, e.g., Maron D J, et al., Cholesterol-Lowering Effect of a Theaflavin-Enriched Green Tea Extract: a Randomized Controlled Trial, Arch. Intern. Med. 163 (12): 1448 (2003). See, also, Lorentz, M., et al., Basic Res Cardiol. 2009 January; 104(1):100; Manna, S., et al., J Nutr Biochem. 2009 May; 20(5):337.
Limited availability of theaflavins, economically derived from natural sources, however, presents a significant barrier to realization of the health benefits of theaflavins. Commercial reagents such as polyphenol peroxidase and hydrogen peroxide from commercial sources are often used in the fermentation step, which further increases the cost of the production. Goodsall, et al., U.S. Pat. Nos. 6,833,144; 6,113,965. Many current extraction and purification steps employ environmentally unfriendly solvents methanol and chloroform. Environmental hazards moreover result from current processes due to the frequent application of strong acids and bases and large amounts of resulting waste generated.
An ongoing need for low cost, high yield, environmentally friendly scalable production of theaflavins from natural sources indeed exists toward realization of numerous health benefits.